Rotary crane

ABSTRACT

In a crane wherein an upper carriage is rotatably supported on a base and an elevated boom has at least one supporting strut deriving a vertical reference from a point offset from the axis of crane rotation, the invention provides at such reference a member slidably guided in the carriage and having roller contact with the base. The arrangement is such as to enable boom loading to be sustained directly by the base, regardless of the rotary position of the crane and regardless of such unevenness as may exist in the path of roller contact about the rotary axis of the crane.

United States Patent [1 1 Scheuerpflug ROTARY CRANE [75] Inventor: HansScheuerpflug, Bad

Mingolsheim, Germany [73] Assignee: Firma Johannes Fuchs, Ditzingen,

Baden-Wurttemberg, Germany 22 Filed: Jan. 10, 1972 21 Appl. No.: 216,592

[30] Foreign Application Priority Data 6/1877 Kirkam 212/47 Oct. 9, 1973FOREIGN PATENTS OR APPLICATIONS 2,279 9/1856 Great Britain 212166894,681 4/1962 Great Britain 212/35 Primary Examiner-Even C. BlunkAssistant Examiner-H. Lane Attorney-Nichol M. Sandoe et a1..

[57] ABSTRACT In a crane wherein an upper carriage is rotatablysupported on a base and an elevated boom has at least one supportingstrut deriving a vertical reference from a point offset from the axis-ofcrane rotation, the invention provides at such reference a memberslidably guided in the carriage and having roller contact with the base.The arrangement is such as to enable boom loading to be sustaineddirectly by the base, regardless of the rotary position of the crane andregardless of such unevenness as may exist in the path of roller contactabout the rotary axis of the crane.

10 Claims, 4 Drawing Figures ROTARY CRANE cated at a greater distancefrom the axis of rotation of the upper carriage, it is known to providethe intermediate piece, directly alongside the point of connection forthe boom, with rollers which rest against the undercarriage of thecrane.

This known supporting of the boom on the base by means of a roller,however, requires a relatively large base since, as a result of the useof the intermediate piece, the supporting roller rests on the baserelatively far from the axis of rotation of the upper carriage. For thisreason, in the known rotary crane it is necessary to provide platformswhich can be connected with the base and on which the rollers cantravel.

In other known rotary cranes, the boom is supported entirely on theupper carriage so that the upper carriage must sustain the entire loadmoment. Such a configuration requires that the upper carriage and theslewing track ring connected with the base must be made correspondinglyheavy, which has a detrimental effect on the cost of the crane.

The object of the invention is to provide a rotary crane in which theupper carriage can be developed as small and light as possible, and inwhich the support for the upper carriage need not sustain the entireload moment of the boom.

This object is attained in a rotary crane of the aforementioned type inaccordance with the present invention in the manner that for thesupportingof the boom there is provided a supporting member or pin whichis axially displaceably guided by the upper carriage, the guide axisforming an angle with the horizontal (i.e., being upwardly directed) andthe roller being carried by the end thereof which faces the base. Inthis way the result is obtained that, without having to increase thesize of the upper carriage substantially, the latter need not sustainthe entire load moment of the boom.

In this connection, a guide boom can be supported directly on the end ofa supporting guided pin extending upwardly and away from the roller. Ina rotary crane in which one end of the boom is supported directly on theupper carriage and an extendable strut, e.g., lift-cylinder mechanism,acts on it at a distance from the boom support, the end of thelift-cylinder mechanism facing away from the boom can be supported onthe supporting pin. In this way, the entire load to be taken up by thelift-cylinder mechanism is supported via the lift pin and the roller onthe lower carriage or base.

The invention makes possible the design of an upper carriage ofextremely small size, in which case it is also possible to provide araceway or track (for the supporting roller) of the smallest possiblediameter; as a result, the width of the base, for instance of a lowerciarriage, can also be reduced.

The invention will be explained in detail in the following descriptionof greatly simplified embodiments of rotary cranes in accordance withthe invention, shown schematically in the drawing in which: 1

FIG. 1 is a side view in elevation of a first embodiment;

FIGS. 2 and 3 are an enlarged fragmentary side and front views,respectively broken away and partially in section, of the front end ofthe upper carriage of the embodiment of FIG. 1 supported rotatably on abase;

FIG. 4 is a view corresponding to FIG. 2 to illustrate a secondembodiment.

On a chassis 1 serving as base, an upper carriage 3 is supported bymeans of a slewing ring 2 for rotation around a vertical axis 4, a boom5 being supported on said upper carriage for swinging around ahorizontal axis 6.

At its front end, the upper carriage 3 has two exten sions 7 and 7a,respectively provided with square guide openings 8 and 8a, thelongitudinal axes of which extend upwardly, being practically verticaland thus forming an angle with the horizontal; the guide axes aresubstantially in the vertical plane of the boom 5 and the axis 4 ofcrane rotation, being preferably inclined slightly away from axis 4, asshown. In these openings 8 and 8a, there are supported for axialdisplacement square guide members, pins or bolts 9 and 9a, each of whichis suitably bushed, as suggested at 21-22, and bears at its lower end afork 11 (11a) in which a roller 12 (12a) is supported for rotation. Theaxis of rotation of each of-the two rollers 12 and 12a extendssubstantially horizontal and radial to the axis of rotation 4 of theupper carriage 3.

The upper ends of the pins 9 and 9a, i.e., facing away from the rollers12 and 12a, are equipped with ball joints 13 and 13a which serve forpivotally connecting bearing pins 14' and 14a of the cylindrical bodies15 and 15a of liftcylinder mechanisms 16 and 16a with the square pins 9and 9a. The piston rods of the lift cylinders 16 and 16a are, as can benoted from FIG. 1, pivotally connected with the boom 5 at a distanceoffset from the axis 6 of said boom. 1

Due to the fact that the openings 8 and 8a as well as the square pins 9and 9a have substantially identical square cross-section, the axes ofrotation of the rollers l2'and 12a will always be held in such a mannerthat they extend radial to the axis of rotation 4 of the upper carriage3 and in this way can easily travel on a raceway 17 of the chassis l,upon rotation of the upper carriage 3. And since the square pins 9 and9a are axially displaceable in the openings 8 and 8a, there is automaticaccommodation to any and all unevenness or irregularity in the racewayl7, and the upper carriage 3 will not be required to carry that part ofthe weight of the boom 5 which is sustained by the strut orlift-cylinder means 16 and 16a. Due to the fact that the pins 9 and 9acannot turn in the square openings 8 and 8a, the axes of rotation of therollers are at all times held in a radial position with respect to theaxis of rotation 4 of the upper carriage 3 so that a proper rolling ofthe rollers 12 and 12a on the raceway 17 is at all times assured.Instead of the square cross-sections of the pins 9 and 9a and of theopenings 8 and 80, any other known device to prevent rotation, as forexample, by using keyed cylindrical pins 9 and 9a, may be provided.

By supporting the boom 5 on the rollers 12 and 12a, the upper carriage 3is very extensively relieved of load so that it and the slewing track 2can be made lighter and of smaller diameter, thus creating thepossibility of also making the chassis l narrower without therebyreducing the load carrying capacity of the boom.

Instead of two pins 9 and 9a, one single pin can also be provided.lnstead of supporting a lift cylinder for the boom 5 on the upper end ofthe pins 9 and 9a, as in the embodiment shown here, the lower end of theboom can also be supported there in the case of a guided boom or derrickconfiguration.

In the embodiment shown in FIG. 4, all the parts which correspond to theparts of the embodiment shown in FIGS. 1-3 are designated by referencenumbers which have been increased by 100, so that reference may bethereby made to the preceding description.

The embodiment of FIG. 4 differs from the preceding embodiment merely bythe fact that, in this case, bearing supports 118 are rigidly connectedby means of two pins 119 and 120 to the extensions 107 and 107a of theupper carriage 103 for the supporting of the pins 109 and 109a. Thesebearing supports, in the same way as the extensions 7 and 7a of thepreceding embodiment, also have square openings 108 (108a) in which thesquare pins 109 (1090) in the bearing bushings 121-122 can move axiallybut cannot rotate.

What is claimed is:

1. A vehicular rotary crane, comprising an upper carriage rotatablysupported on a chassis includingupwardly facing circular track meansconcentric with the axis of carriage rotation and fully contained withinthe chassis planform, a boom connected to and rotatable with saidcarriage, and boom-supporting means including at least one roller havingrolling contact with said track means, said boom-supporting meansincluding a floating member carrying said roller and movably guided bysaid carriage on an upwardly extending axis offset from the axis ofrotation of said carriage, the base end of the boom being directlysupported on said carriage, and said boom-supporting means including alift cylinder connected to act between said member and a point on saidboom offset from the boom connection to said carriage.

2. A rotary crane according to claim 1, in which said member is a pinslidably guided by said carriage.

3. A rotary crane according to claim 2, in which said pin isnon-rotatably guided.

4. A rotary crane according to claim 2, in which said pin is one of two,said pins being independently guided by said carriage on upwardlyextending axes which are spaced from each other about the rotary axis ofthe crane.

5. A vehicular rotary crane, comprising a chassis frame, an uppercarriage supported for rotary displacement about a vertical axis on saidframe, upper and lower boom members having spaced pivotal connection tosaid carriage and being pivotally connected to each other at a locationoffset from said carriage, an upwardly facing circular track on saidframe about said axis and beneath a radially offset part of saidcarriage, one of said boom-member connections to said carriage being ingenerally vertical overlapping register with the radial offset of saidtrack; said one boom-member connection comprising thrust-sustaining pinmeans positioned by said carriage and having a degree of freedom ofvertically guided movement with respect to said carriage and connectedto the lower end of the applicable boom member, said pin means includingroller means supported for thrust-sustaining rolling contact with saidtrack, whereby said pin means relieves the carriage from a substantialcomponent of the vertical load sustained via said applicable boommember, regardless of unevenness in said track about said axis.

6. A rotary crane according to claim 5, in which the pin member is ofnon-circular section and has a keyed relation to its vertically guidedconnection to said carriage, the axis of said roller being orientedgenerally radially of the axis of carriage-rotation.

7. The crane of claim 12, in which said applicable boom member is one oftwo lower boom members connected at their upper ends to said upper boommember, and in which said thrust-sustaining means is one of two pinmembers slidably guided on upwardly extending axes which are angularlyspaced about the rotary axis of the crane, the respective lower ends ofsaid lower boom members being independently connected to said pinmembers.

8. The crane of claim 12, in which the pin means is guided substantiallyin the vertical plane of boom orientation and is offset from thevertical.

9. A rotary crane according to claim 5, in which said applicable boommember is an extendable strut.

10. The crane of claim 9, in which said extendable strut includes ahydraulic lift cylinder having pinned connection to said member.

1. A vehicular rotary crane, comprising an upper carriage rotatablysupported on a chassis including upwardly facing circular track meansconcentric with the axis of carriage rotation and fully contained withinthe chassis planform, a boom connected to and rotatable with saidcarriage, and boomsupporting means including at least one roller havingrolling contact with said track means, said boom-supporting meansincluding a floating member carrying said roller and movably guided bysaid carriage on an upwardly extending axis offset from the axis ofrotation of said carriage, the base end of the boom being directlysupported on said carriage, and said boomsupporting means including alift cylinder connected to act between said member and a point on saidboom offset from the boom connection to said carriage.
 2. A rotary craneaccording to claim 1, in which said member is a pin slidably guided bysaid carriage.
 3. A rotary crane according to claim 2, in which said pinis non-rotatably guided.
 4. A rotary crane according to claim 2, inwhich said pin is one of two, said pins being independently guided bysaid carriage on upwardly extending axes which are spaced from eachother about the rotary axis of the crane.
 5. A vehicular rotary crane,comprising a chassis frame, an upper carriage supported for rotarydisplacement about a vertical axis on said frame, upper and lower boommembers having spaced pivotal connection to said carriage and beingpivotally connected to each other at a location offset from saidcarriage, an upwardly facing circular track on said frame about saidaxis and beneath a radially offset part of said carriage, one of saidboom-member connections to said carriage being in generally verticaloverlapping register with the radial offset of said track; said oneboom-member connection comprising thrust-sustaining pin means positionedby said carriage and having a degree of freedom of vertically guidedmovement with respect to said carriage and connected to the lower end ofthe applicable boom member, said pin means including roller meanssupported for thrust-sustaining rolling contact with said track, wherebysaid pin means relieves the carriage from a substantial component of thevertical load sustained via said applicable boom member, regardless ofunevenness in said track about said axis.
 6. A rotary crane according toclaim 5, in which the pin member is of non-circular section and has akeyed relation to its vertically guided connection to said carriage, theaxis of said roller being oriented generally radially of the axis ofcarriage-rotation.
 7. The crane of claim 12, in which said applicableboom member is one of two lower boom members connected at their upperends to said upper boom member, and in which said thrust-sustainingmeans is one of two pin members slidably guided on upwardly extendingaxes which are angularly spaced about the rotary axis of the crane, therespective lower ends of said lower boom members being independentlyconnected to said pin members.
 8. The crane of claim 12, in which thepin means is guided substantially in the vertical plane of boomorientation and is offset from the vertical.
 9. A rotary crane accordingto claim 5, in which said applicable boom member is an extendable strut.10. The crane of claim 9, in which said extendable strut includes ahydraulic lift cylinder having pinned connection to said member.